Preparation of 3-D porous fibroin scaffolds by freeze drying with treatment of methanol solutions

In this study, silk scaffolds with appropriate porous structures were prepared by adjusting solution concentrations and providing treatment with methanol solutions in the way of freeze drying. The effects of the preparation conditions on the microstructures and properties of the scaffolds were discussed. Fibroin solutions with different concentrations of 4, 6, 8, 10 wt% were used respectively to prepare the scaffolds. The effects of the addition of 20 vol% methanol before or after freeze drying to the 4 wt% fibroin solution were investigated. As demonstrated by Scanning Electron Microscope (SEM), the fib-roin scaffolds prepared without methanol had porous microstructures composed of thin sheets, and the sizes of the pores decreased with the increase of the fibroin solution concentrations, while the scaffolds prepared in the presence of methanol showed porous microstructures formed by fine-particle aggregates. The porosities and mechanical properties of the prepared fibroin scaffolds under different conditions were tested. The crystalline structures and conformations of the fibroin scaffolds were detected by Fourier transform infrared spectroscopy (FT-IR) and X-ray diffraction (XRD).     

焚烧炉中单元垃圾干燥过程的试验研究

通过在马弗炉内以及循环流化床内对单元垃圾（土豆块）进行干燥试验，分别获得了其在炉内的干燥特性曲线．试验结果显示，在马弗炉内低温区干燥温度对垃圾干燥过程的影响较大；在同一干燥温度下，随着垃圾厚度的增加，干燥时间近似呈指数形式增加；在干燥的大部分阶段，土豆块内温度随含湿量减少呈逐渐上升趋势．在循环流化床内，土豆块的整个干燥过程中只有降速段，而不存在恒速段和初始段，垃圾厚度对干燥过程有显著影响．     

Study on seal improvement and rotor thrust control of centrifugal compressor

Fluid pressure variations due to process fluctuations or balance drum seal degradation can result in rotor thrust increasing that may jeopardize thrust bearing and compressor’s reliability. Also, the leakage flow through balance drum seal can seriously affect the efficiency of compressor. A method that can improve both the efficiency and reliability of centrifugal compressor is presented. The method focused on rotor thrust control and balance drum seal upgrading. The low leakage feature of Dry-Gas-Seal（DGS）, high reliability of labyrinth, and the feasibility of upgrading existing structure are taken into account at the same time to design a combined labyrinth-dry gas seal system on the balancing drum. Based on the combined seal system, a Fault Self-Recovering（FSR） system for the fault of rotor shaft displacement is introduced to assure the safety and reliability of centrifugal compressor. The modern Computational Fluid Dynamics（CFD） is used to validate this envision. The numerical result and relevant information indicate that the combined sealing system could improve the efficiency of the centrifugal compressor by about 4%.     

中药材的常用干燥方法

1．日晒法。这是大多数中药材常用的干燥方法。选择晴朗、有风的天气，将药材薄薄地摊在苇席上或水泥地上，利用日光进行晾晒，要及时翻动，保证日光照射均匀。秋后晾晒中药材时，因夜间空气湿度大，要注意在晚上将药材收起盖好，以防返潮。     

干燥窑温度模糊控制系统的研制

以沈阳市北方机械厂开发的新型木材干燥设备为例，对干燥窑温度的模糊控制方法进行了研究，并提出了智能化模糊控制方案。该系统解决了木材干燥过程中监测管理、热力自动调整等问题。     

3150新闻纸机干燥部提速适应性改造

国产3150新闻纸机干燥部车速从550米／分提高到700米／分存在主要问题：一是纸页横幅水份不均匀波动值大于40％；二是转动负荷增大超载跳停。改造的主要内容是转动件校平衡、提高联动齿轮箱的组装精度、增强烘缸内冷凝水及时排出的功能。     

气凝胶透明绝热材料的研究

本文讨论了气凝胶透明绝热材料的超临界制备过程，并对以往的制备工艺进行了改进。获得的制品具有气孔率高，比表面大，收缩率小，透明度高，导热系数小，催化吸附等特性。测试结果表明：透明度为９０％，气孔率为９５％，比表面为１０００ｍ＾２／ｇ，导热系数为０．０１５－０．０２０Ｗ／ｍｋ，是一种优异的化学材料。     

磷矿干燥尾气除尘技术改造

针对高效氮磷复合肥生产中磷矿干燥装置存在的问题，提出了增加GLD－5型复合式除尘器用于其尾气除尘系统的改造方案，并对改造后的运行情况及效果作了简单介绍。     

马尾松木材的透气性对高温干燥速度的影响

对马尾松木材的横向渗透性进行了测量 ,讨论了马尾松木材的渗透性与高温干燥中水分迁移的关系 ,认为在高温干燥过程中 ,纤维饱和点以上木材的渗透性对干燥过程中水分迁移速度的影响最大 ,纤维饱和点以下木材的渗透性对干燥过程中水分迁移速度的影响较小     

钠基膨润土干燥机理及动力学模型的研究

本文通过膨润土颗粒在悬浮态下干燥的实验测试数据,对该类物料的干燥机理进行了剖析,在此基础上回归了一个半理论半经验的干燥动力学模型.通过电镜、x-射线衍射以及化学分析,探讨了干燥温度对物料结构性能的影响.